Mercedes says that Lewis Hamilton finishing the Russian Grand Prix in second place was a "miracle" as falling water pressure threatened to derail his race.
Hamilton had started from 10th position after an all-night effort from Mercedes following an MGU-H failure in qualifying and had recovered to second when the outfit detected a further problem.
Hamilton backed off to maintain second place, behind Nico Rosberg, and in an open letter to fans, which was posted following criticism from some factions, Mercedes confirmed that the Briton's efforts were "remarkable."
"At the time, he was pushing hard to catch Nico and pull away from Kimi [Raikkonen] – posting several purple lap times in the process," Mercedes confirmed.
"We needed to await confirmation from the FIA of what we could tell him via the radio.
"After several calls asking him to take it easy, the all-clear came to let him know that he was losing water pressure.
"With zero – yes, zero! – water pressure remaining for the last 16 laps, the job he did to nurse the car home and still retain second place was truly remarkable.
"He had to keep the car as cool as possible to avoid damaging the engine whilst also keeping Kimi at a safe distance, which was no mean feat.
"We genuinely aren’t sure by what miracle the car limped across the line – but we’re certainly not going to complain!"